The objectives of the proposed work can be divided into three categories. All are more generally classified as attempts to identify regulatory parameters and their interactions which determine the ordered development of metabolic pathways and which are likely to be the chemical basis of differentiation in higher organisms. One project is an attempt to corroborate the proposal that the simple, aliphatic polyamines (putrescine, spermidine, and spermine) and cyclic adenosine 3', 5'-monophosphate (cAMP) are components of a tightly controlled, negative feedback regulatory loop. A second project is an investigation to demonstrate that the polyamines are determinants of the quality and quantity of nuclear non-histone chromosomal protein phosphorylations in isolated nuclei from Physarum polycephalum, and thus are regulatory factors in genetic transcription. Both of these objectives are extensions of our discovery that a combination of the three polyamines potently inhibit a nuclear adenylate cyclase in P. polycephalum. A third project is a investigation to account for the control of enzyme activity levels during synchronous differentiation and the mitotic cycle of P. polycephalum. The enzymes currently under investigation are UDP-glucose pyrophosphorylase, UDP-glucose-4-epimerase, and beta-N-acetylhexosaminidase. The ultimate goal of this project is to employ indirect immunoprecipatation techniques to analytically determine whether new and concurrent mRNA synthesis is essential for induction of these enzyme activities on initiation of plasmodial differentiation in P. polycephalum. BIBLIOGRAPHIC REFERENCES: Adenylate Cyclases in Physarum polycephalum: Inhibition of a Nuclear Enzyme by Polyamines, V.J. Atmar, J.A. Westland, G. Garcia, and G.D. Kuehn, Biochemical and Biophysical Research Communications 68, 561-568 (1976). Affinity Chromatography with a Boronic Acid Derivative. A General Method Applied to a Simplified Adenylate Cyclase Assay, J.H. Hageman and G.D. Kuehn, Fed. Proc. 35 Abs., 1711 (1976).